Improve Drupal Validation Pipelines with consistent approach

As discussed in our coffee meeting this morning, both teams identified some entropy in the way website validation is done.

Currently the infrastructure team both prepares an image and creates clones of suggested instances to the new version/patch, and requests the webteam to validate it's functionality.

As the webteam currently uses the following repository as part of the validation, the suggestion is to improve the current cern-drupal-distribution pipeline to include these tests, as well do an improvement on them to semi-automatically validate generated clones for each campaign.

The expected new pipeline is to be similar to the following:

graph LR
    classDef roundBox fill:#add8e6,stroke:#333,stroke-width:2px,rx:10,ry:10;

    A[Image Building]:::roundBox
    subgraph Testing
        B1[Infrastructure Validation - New Instances]:::roundBox
        B2[Infrastructure Validation - Existing Instances]:::roundBox
        C1[Application Layer Validation - New Instances]:::roundBox
        C2[Application Layer Validation - Existing Instances]:::roundBox
    end
    A --> B1
    A --> B2
    B1 --> C1
    B2 --> C2
    C1 --> D[Delete All Created Instances]:::roundBox
    C2 --> D[Delete All Created Instances]:::roundBox
    E[Manual Args Added]:::roundBox --> B2